Merge master.kernel.org:/home/rmk/linux-2.6-arm
[linux-2.6] / drivers / scsi / imm.c
1 /* imm.c   --  low level driver for the IOMEGA MatchMaker
2  * parallel port SCSI host adapter.
3  * 
4  * (The IMM is the embedded controller in the ZIP Plus drive.)
5  * 
6  * My unoffical company acronym list is 21 pages long:
7  *      FLA:    Four letter acronym with built in facility for
8  *              future expansion to five letters.
9  */
10
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/blkdev.h>
15 #include <linux/parport.h>
16 #include <linux/workqueue.h>
17 #include <linux/delay.h>
18 #include <asm/io.h>
19
20 #include <scsi/scsi.h>
21 #include <scsi/scsi_cmnd.h>
22 #include <scsi/scsi_device.h>
23 #include <scsi/scsi_host.h>
24
25 /* The following #define is to avoid a clash with hosts.c */
26 #define IMM_PROBE_SPP   0x0001
27 #define IMM_PROBE_PS2   0x0002
28 #define IMM_PROBE_ECR   0x0010
29 #define IMM_PROBE_EPP17 0x0100
30 #define IMM_PROBE_EPP19 0x0200
31
32
33 typedef struct {
34         struct pardevice *dev;  /* Parport device entry         */
35         int base;               /* Actual port address          */
36         int base_hi;            /* Hi Base address for ECP-ISA chipset */
37         int mode;               /* Transfer mode                */
38         struct scsi_cmnd *cur_cmd;      /* Current queued command       */
39         struct delayed_work imm_tq;     /* Polling interrupt stuff       */
40         unsigned long jstart;   /* Jiffies at start             */
41         unsigned failed:1;      /* Failure flag                 */
42         unsigned dp:1;          /* Data phase present           */
43         unsigned rd:1;          /* Read data in data phase      */
44         unsigned wanted:1;      /* Parport sharing busy flag    */
45         wait_queue_head_t *waiting;
46         struct Scsi_Host *host;
47         struct list_head list;
48 } imm_struct;
49
50 static void imm_reset_pulse(unsigned int base);
51 static int device_check(imm_struct *dev);
52
53 #include "imm.h"
54
55 static inline imm_struct *imm_dev(struct Scsi_Host *host)
56 {
57         return *(imm_struct **)&host->hostdata;
58 }
59
60 static DEFINE_SPINLOCK(arbitration_lock);
61
62 static void got_it(imm_struct *dev)
63 {
64         dev->base = dev->dev->port->base;
65         if (dev->cur_cmd)
66                 dev->cur_cmd->SCp.phase = 1;
67         else
68                 wake_up(dev->waiting);
69 }
70
71 static void imm_wakeup(void *ref)
72 {
73         imm_struct *dev = (imm_struct *) ref;
74         unsigned long flags;
75
76         spin_lock_irqsave(&arbitration_lock, flags);
77         if (dev->wanted) {
78                 parport_claim(dev->dev);
79                 got_it(dev);
80                 dev->wanted = 0;
81         }
82         spin_unlock_irqrestore(&arbitration_lock, flags);
83 }
84
85 static int imm_pb_claim(imm_struct *dev)
86 {
87         unsigned long flags;
88         int res = 1;
89         spin_lock_irqsave(&arbitration_lock, flags);
90         if (parport_claim(dev->dev) == 0) {
91                 got_it(dev);
92                 res = 0;
93         }
94         dev->wanted = res;
95         spin_unlock_irqrestore(&arbitration_lock, flags);
96         return res;
97 }
98
99 static void imm_pb_dismiss(imm_struct *dev)
100 {
101         unsigned long flags;
102         int wanted;
103         spin_lock_irqsave(&arbitration_lock, flags);
104         wanted = dev->wanted;
105         dev->wanted = 0;
106         spin_unlock_irqrestore(&arbitration_lock, flags);
107         if (!wanted)
108                 parport_release(dev->dev);
109 }
110
111 static inline void imm_pb_release(imm_struct *dev)
112 {
113         parport_release(dev->dev);
114 }
115
116 /* This is to give the imm driver a way to modify the timings (and other
117  * parameters) by writing to the /proc/scsi/imm/0 file.
118  * Very simple method really... (Too simple, no error checking :( )
119  * Reason: Kernel hackers HATE having to unload and reload modules for
120  * testing...
121  * Also gives a method to use a script to obtain optimum timings (TODO)
122  */
123 static inline int imm_proc_write(imm_struct *dev, char *buffer, int length)
124 {
125         unsigned long x;
126
127         if ((length > 5) && (strncmp(buffer, "mode=", 5) == 0)) {
128                 x = simple_strtoul(buffer + 5, NULL, 0);
129                 dev->mode = x;
130                 return length;
131         }
132         printk("imm /proc: invalid variable\n");
133         return (-EINVAL);
134 }
135
136 static int imm_proc_info(struct Scsi_Host *host, char *buffer, char **start,
137                         off_t offset, int length, int inout)
138 {
139         imm_struct *dev = imm_dev(host);
140         int len = 0;
141
142         if (inout)
143                 return imm_proc_write(dev, buffer, length);
144
145         len += sprintf(buffer + len, "Version : %s\n", IMM_VERSION);
146         len +=
147             sprintf(buffer + len, "Parport : %s\n",
148                     dev->dev->port->name);
149         len +=
150             sprintf(buffer + len, "Mode    : %s\n",
151                     IMM_MODE_STRING[dev->mode]);
152
153         /* Request for beyond end of buffer */
154         if (offset > len)
155                 return 0;
156
157         *start = buffer + offset;
158         len -= offset;
159         if (len > length)
160                 len = length;
161         return len;
162 }
163
164 #if IMM_DEBUG > 0
165 #define imm_fail(x,y) printk("imm: imm_fail(%i) from %s at line %d\n",\
166            y, __func__, __LINE__); imm_fail_func(x,y);
167 static inline void
168 imm_fail_func(imm_struct *dev, int error_code)
169 #else
170 static inline void
171 imm_fail(imm_struct *dev, int error_code)
172 #endif
173 {
174         /* If we fail a device then we trash status / message bytes */
175         if (dev->cur_cmd) {
176                 dev->cur_cmd->result = error_code << 16;
177                 dev->failed = 1;
178         }
179 }
180
181 /*
182  * Wait for the high bit to be set.
183  * 
184  * In principle, this could be tied to an interrupt, but the adapter
185  * doesn't appear to be designed to support interrupts.  We spin on
186  * the 0x80 ready bit. 
187  */
188 static unsigned char imm_wait(imm_struct *dev)
189 {
190         int k;
191         unsigned short ppb = dev->base;
192         unsigned char r;
193
194         w_ctr(ppb, 0x0c);
195
196         k = IMM_SPIN_TMO;
197         do {
198                 r = r_str(ppb);
199                 k--;
200                 udelay(1);
201         }
202         while (!(r & 0x80) && (k));
203
204         /*
205          * STR register (LPT base+1) to SCSI mapping:
206          *
207          * STR      imm     imm
208          * ===================================
209          * 0x80     S_REQ   S_REQ
210          * 0x40     !S_BSY  (????)
211          * 0x20     !S_CD   !S_CD
212          * 0x10     !S_IO   !S_IO
213          * 0x08     (????)  !S_BSY
214          *
215          * imm      imm     meaning
216          * ==================================
217          * 0xf0     0xb8    Bit mask
218          * 0xc0     0x88    ZIP wants more data
219          * 0xd0     0x98    ZIP wants to send more data
220          * 0xe0     0xa8    ZIP is expecting SCSI command data
221          * 0xf0     0xb8    end of transfer, ZIP is sending status
222          */
223         w_ctr(ppb, 0x04);
224         if (k)
225                 return (r & 0xb8);
226
227         /* Counter expired - Time out occurred */
228         imm_fail(dev, DID_TIME_OUT);
229         printk("imm timeout in imm_wait\n");
230         return 0;               /* command timed out */
231 }
232
233 static int imm_negotiate(imm_struct * tmp)
234 {
235         /*
236          * The following is supposedly the IEEE 1284-1994 negotiate
237          * sequence. I have yet to obtain a copy of the above standard
238          * so this is a bit of a guess...
239          *
240          * A fair chunk of this is based on the Linux parport implementation
241          * of IEEE 1284.
242          *
243          * Return 0 if data available
244          *        1 if no data available
245          */
246
247         unsigned short base = tmp->base;
248         unsigned char a, mode;
249
250         switch (tmp->mode) {
251         case IMM_NIBBLE:
252                 mode = 0x00;
253                 break;
254         case IMM_PS2:
255                 mode = 0x01;
256                 break;
257         default:
258                 return 0;
259         }
260
261         w_ctr(base, 0x04);
262         udelay(5);
263         w_dtr(base, mode);
264         udelay(100);
265         w_ctr(base, 0x06);
266         udelay(5);
267         a = (r_str(base) & 0x20) ? 0 : 1;
268         udelay(5);
269         w_ctr(base, 0x07);
270         udelay(5);
271         w_ctr(base, 0x06);
272
273         if (a) {
274                 printk
275                     ("IMM: IEEE1284 negotiate indicates no data available.\n");
276                 imm_fail(tmp, DID_ERROR);
277         }
278         return a;
279 }
280
281 /* 
282  * Clear EPP timeout bit. 
283  */
284 static inline void epp_reset(unsigned short ppb)
285 {
286         int i;
287
288         i = r_str(ppb);
289         w_str(ppb, i);
290         w_str(ppb, i & 0xfe);
291 }
292
293 /* 
294  * Wait for empty ECP fifo (if we are in ECP fifo mode only)
295  */
296 static inline void ecp_sync(imm_struct *dev)
297 {
298         int i, ppb_hi = dev->base_hi;
299
300         if (ppb_hi == 0)
301                 return;
302
303         if ((r_ecr(ppb_hi) & 0xe0) == 0x60) {   /* mode 011 == ECP fifo mode */
304                 for (i = 0; i < 100; i++) {
305                         if (r_ecr(ppb_hi) & 0x01)
306                                 return;
307                         udelay(5);
308                 }
309                 printk("imm: ECP sync failed as data still present in FIFO.\n");
310         }
311 }
312
313 static int imm_byte_out(unsigned short base, const char *buffer, int len)
314 {
315         int i;
316
317         w_ctr(base, 0x4);       /* apparently a sane mode */
318         for (i = len >> 1; i; i--) {
319                 w_dtr(base, *buffer++);
320                 w_ctr(base, 0x5);       /* Drop STROBE low */
321                 w_dtr(base, *buffer++);
322                 w_ctr(base, 0x0);       /* STROBE high + INIT low */
323         }
324         w_ctr(base, 0x4);       /* apparently a sane mode */
325         return 1;               /* All went well - we hope! */
326 }
327
328 static int imm_nibble_in(unsigned short base, char *buffer, int len)
329 {
330         unsigned char l;
331         int i;
332
333         /*
334          * The following is based on documented timing signals
335          */
336         w_ctr(base, 0x4);
337         for (i = len; i; i--) {
338                 w_ctr(base, 0x6);
339                 l = (r_str(base) & 0xf0) >> 4;
340                 w_ctr(base, 0x5);
341                 *buffer++ = (r_str(base) & 0xf0) | l;
342                 w_ctr(base, 0x4);
343         }
344         return 1;               /* All went well - we hope! */
345 }
346
347 static int imm_byte_in(unsigned short base, char *buffer, int len)
348 {
349         int i;
350
351         /*
352          * The following is based on documented timing signals
353          */
354         w_ctr(base, 0x4);
355         for (i = len; i; i--) {
356                 w_ctr(base, 0x26);
357                 *buffer++ = r_dtr(base);
358                 w_ctr(base, 0x25);
359         }
360         return 1;               /* All went well - we hope! */
361 }
362
363 static int imm_out(imm_struct *dev, char *buffer, int len)
364 {
365         unsigned short ppb = dev->base;
366         int r = imm_wait(dev);
367
368         /*
369          * Make sure that:
370          * a) the SCSI bus is BUSY (device still listening)
371          * b) the device is listening
372          */
373         if ((r & 0x18) != 0x08) {
374                 imm_fail(dev, DID_ERROR);
375                 printk("IMM: returned SCSI status %2x\n", r);
376                 return 0;
377         }
378         switch (dev->mode) {
379         case IMM_EPP_32:
380         case IMM_EPP_16:
381         case IMM_EPP_8:
382                 epp_reset(ppb);
383                 w_ctr(ppb, 0x4);
384 #ifdef CONFIG_SCSI_IZIP_EPP16
385                 if (!(((long) buffer | len) & 0x01))
386                         outsw(ppb + 4, buffer, len >> 1);
387 #else
388                 if (!(((long) buffer | len) & 0x03))
389                         outsl(ppb + 4, buffer, len >> 2);
390 #endif
391                 else
392                         outsb(ppb + 4, buffer, len);
393                 w_ctr(ppb, 0xc);
394                 r = !(r_str(ppb) & 0x01);
395                 w_ctr(ppb, 0xc);
396                 ecp_sync(dev);
397                 break;
398
399         case IMM_NIBBLE:
400         case IMM_PS2:
401                 /* 8 bit output, with a loop */
402                 r = imm_byte_out(ppb, buffer, len);
403                 break;
404
405         default:
406                 printk("IMM: bug in imm_out()\n");
407                 r = 0;
408         }
409         return r;
410 }
411
412 static int imm_in(imm_struct *dev, char *buffer, int len)
413 {
414         unsigned short ppb = dev->base;
415         int r = imm_wait(dev);
416
417         /*
418          * Make sure that:
419          * a) the SCSI bus is BUSY (device still listening)
420          * b) the device is sending data
421          */
422         if ((r & 0x18) != 0x18) {
423                 imm_fail(dev, DID_ERROR);
424                 return 0;
425         }
426         switch (dev->mode) {
427         case IMM_NIBBLE:
428                 /* 4 bit input, with a loop */
429                 r = imm_nibble_in(ppb, buffer, len);
430                 w_ctr(ppb, 0xc);
431                 break;
432
433         case IMM_PS2:
434                 /* 8 bit input, with a loop */
435                 r = imm_byte_in(ppb, buffer, len);
436                 w_ctr(ppb, 0xc);
437                 break;
438
439         case IMM_EPP_32:
440         case IMM_EPP_16:
441         case IMM_EPP_8:
442                 epp_reset(ppb);
443                 w_ctr(ppb, 0x24);
444 #ifdef CONFIG_SCSI_IZIP_EPP16
445                 if (!(((long) buffer | len) & 0x01))
446                         insw(ppb + 4, buffer, len >> 1);
447 #else
448                 if (!(((long) buffer | len) & 0x03))
449                         insl(ppb + 4, buffer, len >> 2);
450 #endif
451                 else
452                         insb(ppb + 4, buffer, len);
453                 w_ctr(ppb, 0x2c);
454                 r = !(r_str(ppb) & 0x01);
455                 w_ctr(ppb, 0x2c);
456                 ecp_sync(dev);
457                 break;
458
459         default:
460                 printk("IMM: bug in imm_ins()\n");
461                 r = 0;
462                 break;
463         }
464         return r;
465 }
466
467 static int imm_cpp(unsigned short ppb, unsigned char b)
468 {
469         /*
470          * Comments on udelay values refer to the
471          * Command Packet Protocol (CPP) timing diagram.
472          */
473
474         unsigned char s1, s2, s3;
475         w_ctr(ppb, 0x0c);
476         udelay(2);              /* 1 usec - infinite */
477         w_dtr(ppb, 0xaa);
478         udelay(10);             /* 7 usec - infinite */
479         w_dtr(ppb, 0x55);
480         udelay(10);             /* 7 usec - infinite */
481         w_dtr(ppb, 0x00);
482         udelay(10);             /* 7 usec - infinite */
483         w_dtr(ppb, 0xff);
484         udelay(10);             /* 7 usec - infinite */
485         s1 = r_str(ppb) & 0xb8;
486         w_dtr(ppb, 0x87);
487         udelay(10);             /* 7 usec - infinite */
488         s2 = r_str(ppb) & 0xb8;
489         w_dtr(ppb, 0x78);
490         udelay(10);             /* 7 usec - infinite */
491         s3 = r_str(ppb) & 0x38;
492         /*
493          * Values for b are:
494          * 0000 00aa    Assign address aa to current device
495          * 0010 00aa    Select device aa in EPP Winbond mode
496          * 0010 10aa    Select device aa in EPP mode
497          * 0011 xxxx    Deselect all devices
498          * 0110 00aa    Test device aa
499          * 1101 00aa    Select device aa in ECP mode
500          * 1110 00aa    Select device aa in Compatible mode
501          */
502         w_dtr(ppb, b);
503         udelay(2);              /* 1 usec - infinite */
504         w_ctr(ppb, 0x0c);
505         udelay(10);             /* 7 usec - infinite */
506         w_ctr(ppb, 0x0d);
507         udelay(2);              /* 1 usec - infinite */
508         w_ctr(ppb, 0x0c);
509         udelay(10);             /* 7 usec - infinite */
510         w_dtr(ppb, 0xff);
511         udelay(10);             /* 7 usec - infinite */
512
513         /*
514          * The following table is electrical pin values.
515          * (BSY is inverted at the CTR register)
516          *
517          *       BSY  ACK  POut SEL  Fault
518          * S1    0    X    1    1    1
519          * S2    1    X    0    1    1
520          * S3    L    X    1    1    S
521          *
522          * L => Last device in chain
523          * S => Selected
524          *
525          * Observered values for S1,S2,S3 are:
526          * Disconnect => f8/58/78
527          * Connect    => f8/58/70
528          */
529         if ((s1 == 0xb8) && (s2 == 0x18) && (s3 == 0x30))
530                 return 1;       /* Connected */
531         if ((s1 == 0xb8) && (s2 == 0x18) && (s3 == 0x38))
532                 return 0;       /* Disconnected */
533
534         return -1;              /* No device present */
535 }
536
537 static inline int imm_connect(imm_struct *dev, int flag)
538 {
539         unsigned short ppb = dev->base;
540
541         imm_cpp(ppb, 0xe0);     /* Select device 0 in compatible mode */
542         imm_cpp(ppb, 0x30);     /* Disconnect all devices */
543
544         if ((dev->mode == IMM_EPP_8) ||
545             (dev->mode == IMM_EPP_16) ||
546             (dev->mode == IMM_EPP_32))
547                 return imm_cpp(ppb, 0x28);      /* Select device 0 in EPP mode */
548         return imm_cpp(ppb, 0xe0);      /* Select device 0 in compatible mode */
549 }
550
551 static void imm_disconnect(imm_struct *dev)
552 {
553         imm_cpp(dev->base, 0x30);       /* Disconnect all devices */
554 }
555
556 static int imm_select(imm_struct *dev, int target)
557 {
558         int k;
559         unsigned short ppb = dev->base;
560
561         /*
562          * Firstly we want to make sure there is nothing
563          * holding onto the SCSI bus.
564          */
565         w_ctr(ppb, 0xc);
566
567         k = IMM_SELECT_TMO;
568         do {
569                 k--;
570         } while ((r_str(ppb) & 0x08) && (k));
571
572         if (!k)
573                 return 0;
574
575         /*
576          * Now assert the SCSI ID (HOST and TARGET) on the data bus
577          */
578         w_ctr(ppb, 0x4);
579         w_dtr(ppb, 0x80 | (1 << target));
580         udelay(1);
581
582         /*
583          * Deassert SELIN first followed by STROBE
584          */
585         w_ctr(ppb, 0xc);
586         w_ctr(ppb, 0xd);
587
588         /*
589          * ACK should drop low while SELIN is deasserted.
590          * FAULT should drop low when the SCSI device latches the bus.
591          */
592         k = IMM_SELECT_TMO;
593         do {
594                 k--;
595         }
596         while (!(r_str(ppb) & 0x08) && (k));
597
598         /*
599          * Place the interface back into a sane state (status mode)
600          */
601         w_ctr(ppb, 0xc);
602         return (k) ? 1 : 0;
603 }
604
605 static int imm_init(imm_struct *dev)
606 {
607         if (imm_connect(dev, 0) != 1)
608                 return -EIO;
609         imm_reset_pulse(dev->base);
610         mdelay(1);      /* Delay to allow devices to settle */
611         imm_disconnect(dev);
612         mdelay(1);      /* Another delay to allow devices to settle */
613         return device_check(dev);
614 }
615
616 static inline int imm_send_command(struct scsi_cmnd *cmd)
617 {
618         imm_struct *dev = imm_dev(cmd->device->host);
619         int k;
620
621         /* NOTE: IMM uses byte pairs */
622         for (k = 0; k < cmd->cmd_len; k += 2)
623                 if (!imm_out(dev, &cmd->cmnd[k], 2))
624                         return 0;
625         return 1;
626 }
627
628 /*
629  * The bulk flag enables some optimisations in the data transfer loops,
630  * it should be true for any command that transfers data in integral
631  * numbers of sectors.
632  * 
633  * The driver appears to remain stable if we speed up the parallel port
634  * i/o in this function, but not elsewhere.
635  */
636 static int imm_completion(struct scsi_cmnd *cmd)
637 {
638         /* Return codes:
639          * -1     Error
640          *  0     Told to schedule
641          *  1     Finished data transfer
642          */
643         imm_struct *dev = imm_dev(cmd->device->host);
644         unsigned short ppb = dev->base;
645         unsigned long start_jiffies = jiffies;
646
647         unsigned char r, v;
648         int fast, bulk, status;
649
650         v = cmd->cmnd[0];
651         bulk = ((v == READ_6) ||
652                 (v == READ_10) || (v == WRITE_6) || (v == WRITE_10));
653
654         /*
655          * We only get here if the drive is ready to comunicate,
656          * hence no need for a full imm_wait.
657          */
658         w_ctr(ppb, 0x0c);
659         r = (r_str(ppb) & 0xb8);
660
661         /*
662          * while (device is not ready to send status byte)
663          *     loop;
664          */
665         while (r != (unsigned char) 0xb8) {
666                 /*
667                  * If we have been running for more than a full timer tick
668                  * then take a rest.
669                  */
670                 if (time_after(jiffies, start_jiffies + 1))
671                         return 0;
672
673                 /*
674                  * FAIL if:
675                  * a) Drive status is screwy (!ready && !present)
676                  * b) Drive is requesting/sending more data than expected
677                  */
678                 if (((r & 0x88) != 0x88) || (cmd->SCp.this_residual <= 0)) {
679                         imm_fail(dev, DID_ERROR);
680                         return -1;      /* ERROR_RETURN */
681                 }
682                 /* determine if we should use burst I/O */
683                 if (dev->rd == 0) {
684                         fast = (bulk
685                                 && (cmd->SCp.this_residual >=
686                                     IMM_BURST_SIZE)) ? IMM_BURST_SIZE : 2;
687                         status = imm_out(dev, cmd->SCp.ptr, fast);
688                 } else {
689                         fast = (bulk
690                                 && (cmd->SCp.this_residual >=
691                                     IMM_BURST_SIZE)) ? IMM_BURST_SIZE : 1;
692                         status = imm_in(dev, cmd->SCp.ptr, fast);
693                 }
694
695                 cmd->SCp.ptr += fast;
696                 cmd->SCp.this_residual -= fast;
697
698                 if (!status) {
699                         imm_fail(dev, DID_BUS_BUSY);
700                         return -1;      /* ERROR_RETURN */
701                 }
702                 if (cmd->SCp.buffer && !cmd->SCp.this_residual) {
703                         /* if scatter/gather, advance to the next segment */
704                         if (cmd->SCp.buffers_residual--) {
705                                 cmd->SCp.buffer++;
706                                 cmd->SCp.this_residual =
707                                     cmd->SCp.buffer->length;
708                                 cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
709
710                                 /*
711                                  * Make sure that we transfer even number of bytes
712                                  * otherwise it makes imm_byte_out() messy.
713                                  */
714                                 if (cmd->SCp.this_residual & 0x01)
715                                         cmd->SCp.this_residual++;
716                         }
717                 }
718                 /* Now check to see if the drive is ready to comunicate */
719                 w_ctr(ppb, 0x0c);
720                 r = (r_str(ppb) & 0xb8);
721
722                 /* If not, drop back down to the scheduler and wait a timer tick */
723                 if (!(r & 0x80))
724                         return 0;
725         }
726         return 1;               /* FINISH_RETURN */
727 }
728
729 /*
730  * Since the IMM itself doesn't generate interrupts, we use
731  * the scheduler's task queue to generate a stream of call-backs and
732  * complete the request when the drive is ready.
733  */
734 static void imm_interrupt(struct work_struct *work)
735 {
736         imm_struct *dev = container_of(work, imm_struct, imm_tq.work);
737         struct scsi_cmnd *cmd = dev->cur_cmd;
738         struct Scsi_Host *host = cmd->device->host;
739         unsigned long flags;
740
741         if (imm_engine(dev, cmd)) {
742                 schedule_delayed_work(&dev->imm_tq, 1);
743                 return;
744         }
745         /* Command must of completed hence it is safe to let go... */
746 #if IMM_DEBUG > 0
747         switch ((cmd->result >> 16) & 0xff) {
748         case DID_OK:
749                 break;
750         case DID_NO_CONNECT:
751                 printk("imm: no device at SCSI ID %i\n", cmd->device->id);
752                 break;
753         case DID_BUS_BUSY:
754                 printk("imm: BUS BUSY - EPP timeout detected\n");
755                 break;
756         case DID_TIME_OUT:
757                 printk("imm: unknown timeout\n");
758                 break;
759         case DID_ABORT:
760                 printk("imm: told to abort\n");
761                 break;
762         case DID_PARITY:
763                 printk("imm: parity error (???)\n");
764                 break;
765         case DID_ERROR:
766                 printk("imm: internal driver error\n");
767                 break;
768         case DID_RESET:
769                 printk("imm: told to reset device\n");
770                 break;
771         case DID_BAD_INTR:
772                 printk("imm: bad interrupt (???)\n");
773                 break;
774         default:
775                 printk("imm: bad return code (%02x)\n",
776                        (cmd->result >> 16) & 0xff);
777         }
778 #endif
779
780         if (cmd->SCp.phase > 1)
781                 imm_disconnect(dev);
782
783         imm_pb_dismiss(dev);
784
785         spin_lock_irqsave(host->host_lock, flags);
786         dev->cur_cmd = NULL;
787         cmd->scsi_done(cmd);
788         spin_unlock_irqrestore(host->host_lock, flags);
789         return;
790 }
791
792 static int imm_engine(imm_struct *dev, struct scsi_cmnd *cmd)
793 {
794         unsigned short ppb = dev->base;
795         unsigned char l = 0, h = 0;
796         int retv, x;
797
798         /* First check for any errors that may have occurred
799          * Here we check for internal errors
800          */
801         if (dev->failed)
802                 return 0;
803
804         switch (cmd->SCp.phase) {
805         case 0:         /* Phase 0 - Waiting for parport */
806                 if (time_after(jiffies, dev->jstart + HZ)) {
807                         /*
808                          * We waited more than a second
809                          * for parport to call us
810                          */
811                         imm_fail(dev, DID_BUS_BUSY);
812                         return 0;
813                 }
814                 return 1;       /* wait until imm_wakeup claims parport */
815                 /* Phase 1 - Connected */
816         case 1:
817                 imm_connect(dev, CONNECT_EPP_MAYBE);
818                 cmd->SCp.phase++;
819
820                 /* Phase 2 - We are now talking to the scsi bus */
821         case 2:
822                 if (!imm_select(dev, scmd_id(cmd))) {
823                         imm_fail(dev, DID_NO_CONNECT);
824                         return 0;
825                 }
826                 cmd->SCp.phase++;
827
828                 /* Phase 3 - Ready to accept a command */
829         case 3:
830                 w_ctr(ppb, 0x0c);
831                 if (!(r_str(ppb) & 0x80))
832                         return 1;
833
834                 if (!imm_send_command(cmd))
835                         return 0;
836                 cmd->SCp.phase++;
837
838                 /* Phase 4 - Setup scatter/gather buffers */
839         case 4:
840                 if (scsi_bufflen(cmd)) {
841                         cmd->SCp.buffer = scsi_sglist(cmd);
842                         cmd->SCp.this_residual = cmd->SCp.buffer->length;
843                         cmd->SCp.ptr = sg_virt(cmd->SCp.buffer);
844                 } else {
845                         cmd->SCp.buffer = NULL;
846                         cmd->SCp.this_residual = 0;
847                         cmd->SCp.ptr = NULL;
848                 }
849                 cmd->SCp.buffers_residual = scsi_sg_count(cmd) - 1;
850                 cmd->SCp.phase++;
851                 if (cmd->SCp.this_residual & 0x01)
852                         cmd->SCp.this_residual++;
853                 /* Phase 5 - Pre-Data transfer stage */
854         case 5:
855                 /* Spin lock for BUSY */
856                 w_ctr(ppb, 0x0c);
857                 if (!(r_str(ppb) & 0x80))
858                         return 1;
859
860                 /* Require negotiation for read requests */
861                 x = (r_str(ppb) & 0xb8);
862                 dev->rd = (x & 0x10) ? 1 : 0;
863                 dev->dp = (x & 0x20) ? 0 : 1;
864
865                 if ((dev->dp) && (dev->rd))
866                         if (imm_negotiate(dev))
867                                 return 0;
868                 cmd->SCp.phase++;
869
870                 /* Phase 6 - Data transfer stage */
871         case 6:
872                 /* Spin lock for BUSY */
873                 w_ctr(ppb, 0x0c);
874                 if (!(r_str(ppb) & 0x80))
875                         return 1;
876
877                 if (dev->dp) {
878                         retv = imm_completion(cmd);
879                         if (retv == -1)
880                                 return 0;
881                         if (retv == 0)
882                                 return 1;
883                 }
884                 cmd->SCp.phase++;
885
886                 /* Phase 7 - Post data transfer stage */
887         case 7:
888                 if ((dev->dp) && (dev->rd)) {
889                         if ((dev->mode == IMM_NIBBLE) || (dev->mode == IMM_PS2)) {
890                                 w_ctr(ppb, 0x4);
891                                 w_ctr(ppb, 0xc);
892                                 w_ctr(ppb, 0xe);
893                                 w_ctr(ppb, 0x4);
894                         }
895                 }
896                 cmd->SCp.phase++;
897
898                 /* Phase 8 - Read status/message */
899         case 8:
900                 /* Check for data overrun */
901                 if (imm_wait(dev) != (unsigned char) 0xb8) {
902                         imm_fail(dev, DID_ERROR);
903                         return 0;
904                 }
905                 if (imm_negotiate(dev))
906                         return 0;
907                 if (imm_in(dev, &l, 1)) {       /* read status byte */
908                         /* Check for optional message byte */
909                         if (imm_wait(dev) == (unsigned char) 0xb8)
910                                 imm_in(dev, &h, 1);
911                         cmd->result = (DID_OK << 16) + (l & STATUS_MASK);
912                 }
913                 if ((dev->mode == IMM_NIBBLE) || (dev->mode == IMM_PS2)) {
914                         w_ctr(ppb, 0x4);
915                         w_ctr(ppb, 0xc);
916                         w_ctr(ppb, 0xe);
917                         w_ctr(ppb, 0x4);
918                 }
919                 return 0;       /* Finished */
920                 break;
921
922         default:
923                 printk("imm: Invalid scsi phase\n");
924         }
925         return 0;
926 }
927
928 static int imm_queuecommand(struct scsi_cmnd *cmd,
929                 void (*done)(struct scsi_cmnd *))
930 {
931         imm_struct *dev = imm_dev(cmd->device->host);
932
933         if (dev->cur_cmd) {
934                 printk("IMM: bug in imm_queuecommand\n");
935                 return 0;
936         }
937         dev->failed = 0;
938         dev->jstart = jiffies;
939         dev->cur_cmd = cmd;
940         cmd->scsi_done = done;
941         cmd->result = DID_ERROR << 16;  /* default return code */
942         cmd->SCp.phase = 0;     /* bus free */
943
944         schedule_delayed_work(&dev->imm_tq, 0);
945
946         imm_pb_claim(dev);
947
948         return 0;
949 }
950
951 /*
952  * Apparently the disk->capacity attribute is off by 1 sector 
953  * for all disk drives.  We add the one here, but it should really
954  * be done in sd.c.  Even if it gets fixed there, this will still
955  * work.
956  */
957 static int imm_biosparam(struct scsi_device *sdev, struct block_device *dev,
958                          sector_t capacity, int ip[])
959 {
960         ip[0] = 0x40;
961         ip[1] = 0x20;
962         ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
963         if (ip[2] > 1024) {
964                 ip[0] = 0xff;
965                 ip[1] = 0x3f;
966                 ip[2] = ((unsigned long) capacity + 1) / (ip[0] * ip[1]);
967         }
968         return 0;
969 }
970
971 static int imm_abort(struct scsi_cmnd *cmd)
972 {
973         imm_struct *dev = imm_dev(cmd->device->host);
974         /*
975          * There is no method for aborting commands since Iomega
976          * have tied the SCSI_MESSAGE line high in the interface
977          */
978
979         switch (cmd->SCp.phase) {
980         case 0:         /* Do not have access to parport */
981         case 1:         /* Have not connected to interface */
982                 dev->cur_cmd = NULL;    /* Forget the problem */
983                 return SUCCESS;
984                 break;
985         default:                /* SCSI command sent, can not abort */
986                 return FAILED;
987                 break;
988         }
989 }
990
991 static void imm_reset_pulse(unsigned int base)
992 {
993         w_ctr(base, 0x04);
994         w_dtr(base, 0x40);
995         udelay(1);
996         w_ctr(base, 0x0c);
997         w_ctr(base, 0x0d);
998         udelay(50);
999         w_ctr(base, 0x0c);
1000         w_ctr(base, 0x04);
1001 }
1002
1003 static int imm_reset(struct scsi_cmnd *cmd)
1004 {
1005         imm_struct *dev = imm_dev(cmd->device->host);
1006
1007         if (cmd->SCp.phase)
1008                 imm_disconnect(dev);
1009         dev->cur_cmd = NULL;    /* Forget the problem */
1010
1011         imm_connect(dev, CONNECT_NORMAL);
1012         imm_reset_pulse(dev->base);
1013         mdelay(1);              /* device settle delay */
1014         imm_disconnect(dev);
1015         mdelay(1);              /* device settle delay */
1016         return SUCCESS;
1017 }
1018
1019 static int device_check(imm_struct *dev)
1020 {
1021         /* This routine looks for a device and then attempts to use EPP
1022            to send a command. If all goes as planned then EPP is available. */
1023
1024         static char cmd[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
1025         int loop, old_mode, status, k, ppb = dev->base;
1026         unsigned char l;
1027
1028         old_mode = dev->mode;
1029         for (loop = 0; loop < 8; loop++) {
1030                 /* Attempt to use EPP for Test Unit Ready */
1031                 if ((ppb & 0x0007) == 0x0000)
1032                         dev->mode = IMM_EPP_32;
1033
1034               second_pass:
1035                 imm_connect(dev, CONNECT_EPP_MAYBE);
1036                 /* Select SCSI device */
1037                 if (!imm_select(dev, loop)) {
1038                         imm_disconnect(dev);
1039                         continue;
1040                 }
1041                 printk("imm: Found device at ID %i, Attempting to use %s\n",
1042                        loop, IMM_MODE_STRING[dev->mode]);
1043
1044                 /* Send SCSI command */
1045                 status = 1;
1046                 w_ctr(ppb, 0x0c);
1047                 for (l = 0; (l < 3) && (status); l++)
1048                         status = imm_out(dev, &cmd[l << 1], 2);
1049
1050                 if (!status) {
1051                         imm_disconnect(dev);
1052                         imm_connect(dev, CONNECT_EPP_MAYBE);
1053                         imm_reset_pulse(dev->base);
1054                         udelay(1000);
1055                         imm_disconnect(dev);
1056                         udelay(1000);
1057                         if (dev->mode == IMM_EPP_32) {
1058                                 dev->mode = old_mode;
1059                                 goto second_pass;
1060                         }
1061                         printk("imm: Unable to establish communication\n");
1062                         return -EIO;
1063                 }
1064                 w_ctr(ppb, 0x0c);
1065
1066                 k = 1000000;    /* 1 Second */
1067                 do {
1068                         l = r_str(ppb);
1069                         k--;
1070                         udelay(1);
1071                 } while (!(l & 0x80) && (k));
1072
1073                 l &= 0xb8;
1074
1075                 if (l != 0xb8) {
1076                         imm_disconnect(dev);
1077                         imm_connect(dev, CONNECT_EPP_MAYBE);
1078                         imm_reset_pulse(dev->base);
1079                         udelay(1000);
1080                         imm_disconnect(dev);
1081                         udelay(1000);
1082                         if (dev->mode == IMM_EPP_32) {
1083                                 dev->mode = old_mode;
1084                                 goto second_pass;
1085                         }
1086                         printk
1087                             ("imm: Unable to establish communication\n");
1088                         return -EIO;
1089                 }
1090                 imm_disconnect(dev);
1091                 printk
1092                     ("imm: Communication established at 0x%x with ID %i using %s\n",
1093                      ppb, loop, IMM_MODE_STRING[dev->mode]);
1094                 imm_connect(dev, CONNECT_EPP_MAYBE);
1095                 imm_reset_pulse(dev->base);
1096                 udelay(1000);
1097                 imm_disconnect(dev);
1098                 udelay(1000);
1099                 return 0;
1100         }
1101         printk("imm: No devices found\n");
1102         return -ENODEV;
1103 }
1104
1105 /*
1106  * imm cannot deal with highmem, so this causes all IO pages for this host
1107  * to reside in low memory (hence mapped)
1108  */
1109 static int imm_adjust_queue(struct scsi_device *device)
1110 {
1111         blk_queue_bounce_limit(device->request_queue, BLK_BOUNCE_HIGH);
1112         return 0;
1113 }
1114
1115 static struct scsi_host_template imm_template = {
1116         .module                 = THIS_MODULE,
1117         .proc_name              = "imm",
1118         .proc_info              = imm_proc_info,
1119         .name                   = "Iomega VPI2 (imm) interface",
1120         .queuecommand           = imm_queuecommand,
1121         .eh_abort_handler       = imm_abort,
1122         .eh_bus_reset_handler   = imm_reset,
1123         .eh_host_reset_handler  = imm_reset,
1124         .bios_param             = imm_biosparam,
1125         .this_id                = 7,
1126         .sg_tablesize           = SG_ALL,
1127         .cmd_per_lun            = 1,
1128         .use_clustering         = ENABLE_CLUSTERING,
1129         .can_queue              = 1,
1130         .slave_alloc            = imm_adjust_queue,
1131 };
1132
1133 /***************************************************************************
1134  *                   Parallel port probing routines                        *
1135  ***************************************************************************/
1136
1137 static LIST_HEAD(imm_hosts);
1138
1139 static int __imm_attach(struct parport *pb)
1140 {
1141         struct Scsi_Host *host;
1142         imm_struct *dev;
1143         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(waiting);
1144         DEFINE_WAIT(wait);
1145         int ports;
1146         int modes, ppb;
1147         int err = -ENOMEM;
1148
1149         init_waitqueue_head(&waiting);
1150
1151         dev = kzalloc(sizeof(imm_struct), GFP_KERNEL);
1152         if (!dev)
1153                 return -ENOMEM;
1154
1155
1156         dev->base = -1;
1157         dev->mode = IMM_AUTODETECT;
1158         INIT_LIST_HEAD(&dev->list);
1159
1160         dev->dev = parport_register_device(pb, "imm", NULL, imm_wakeup,
1161                                                 NULL, 0, dev);
1162
1163         if (!dev->dev)
1164                 goto out;
1165
1166
1167         /* Claim the bus so it remembers what we do to the control
1168          * registers. [ CTR and ECP ]
1169          */
1170         err = -EBUSY;
1171         dev->waiting = &waiting;
1172         prepare_to_wait(&waiting, &wait, TASK_UNINTERRUPTIBLE);
1173         if (imm_pb_claim(dev))
1174                 schedule_timeout(3 * HZ);
1175         if (dev->wanted) {
1176                 printk(KERN_ERR "imm%d: failed to claim parport because "
1177                         "a pardevice is owning the port for too long "
1178                         "time!\n", pb->number);
1179                 imm_pb_dismiss(dev);
1180                 dev->waiting = NULL;
1181                 finish_wait(&waiting, &wait);
1182                 goto out1;
1183         }
1184         dev->waiting = NULL;
1185         finish_wait(&waiting, &wait);
1186         ppb = dev->base = dev->dev->port->base;
1187         dev->base_hi = dev->dev->port->base_hi;
1188         w_ctr(ppb, 0x0c);
1189         modes = dev->dev->port->modes;
1190
1191         /* Mode detection works up the chain of speed
1192          * This avoids a nasty if-then-else-if-... tree
1193          */
1194         dev->mode = IMM_NIBBLE;
1195
1196         if (modes & PARPORT_MODE_TRISTATE)
1197                 dev->mode = IMM_PS2;
1198
1199         /* Done configuration */
1200
1201         err = imm_init(dev);
1202
1203         imm_pb_release(dev);
1204
1205         if (err)
1206                 goto out1;
1207
1208         /* now the glue ... */
1209         if (dev->mode == IMM_NIBBLE || dev->mode == IMM_PS2)
1210                 ports = 3;
1211         else
1212                 ports = 8;
1213
1214         INIT_DELAYED_WORK(&dev->imm_tq, imm_interrupt);
1215
1216         err = -ENOMEM;
1217         host = scsi_host_alloc(&imm_template, sizeof(imm_struct *));
1218         if (!host)
1219                 goto out1;
1220         host->io_port = pb->base;
1221         host->n_io_port = ports;
1222         host->dma_channel = -1;
1223         host->unique_id = pb->number;
1224         *(imm_struct **)&host->hostdata = dev;
1225         dev->host = host;
1226         list_add_tail(&dev->list, &imm_hosts);
1227         err = scsi_add_host(host, NULL);
1228         if (err)
1229                 goto out2;
1230         scsi_scan_host(host);
1231         return 0;
1232
1233 out2:
1234         list_del_init(&dev->list);
1235         scsi_host_put(host);
1236 out1:
1237         parport_unregister_device(dev->dev);
1238 out:
1239         kfree(dev);
1240         return err;
1241 }
1242
1243 static void imm_attach(struct parport *pb)
1244 {
1245         __imm_attach(pb);
1246 }
1247
1248 static void imm_detach(struct parport *pb)
1249 {
1250         imm_struct *dev;
1251         list_for_each_entry(dev, &imm_hosts, list) {
1252                 if (dev->dev->port == pb) {
1253                         list_del_init(&dev->list);
1254                         scsi_remove_host(dev->host);
1255                         scsi_host_put(dev->host);
1256                         parport_unregister_device(dev->dev);
1257                         kfree(dev);
1258                         break;
1259                 }
1260         }
1261 }
1262
1263 static struct parport_driver imm_driver = {
1264         .name   = "imm",
1265         .attach = imm_attach,
1266         .detach = imm_detach,
1267 };
1268
1269 static int __init imm_driver_init(void)
1270 {
1271         printk("imm: Version %s\n", IMM_VERSION);
1272         return parport_register_driver(&imm_driver);
1273 }
1274
1275 static void __exit imm_driver_exit(void)
1276 {
1277         parport_unregister_driver(&imm_driver);
1278 }
1279
1280 module_init(imm_driver_init);
1281 module_exit(imm_driver_exit);
1282
1283 MODULE_LICENSE("GPL");